[Study on tissue culture system of Polygonatum cyrtonema].

In order to accelerate the breeding of the excellent seedlings of Polygonatum cyrtonema,tissue culture system of P. cyrtonema was established through the comprehensive regulation of key factors( leaf age,leaf location,basic media and plant growth regulators) and cytological basis of callus formation and differentiation was analyzed through paraffin section. The results showed that the 30-day-old leaf base explanton medium MS+6-BA 1. 50 mg·L~(-1)+2,4-D 0. 20 mg·L~(-1) had the highest induction rate( 80. 00%). The callus was initiated from cells on leaf base epidermis and near cortex,formed by the differentiation of middle vascular bundle cells. The optimal medium for adventitious bud differentiation was MS+ 6-BA 4. 00 mg·L~(-1)+ 2,4-D 0. 20 mg·L~(-1) with the differentiation rate of90. 33%,and the average number of buds was 5. 16. The adventitious buds had two origin types: exogenous and endogenous origin,formed by callus proximal cells and callus internal meristemoid. The adventitious bud proliferation medium was screened by orthogonal design,which determined the optimum combination was MS+ 6-BA 2. 00 mg·L~(-1)+NAA 0. 10 mg·L~(-1) and MS+ 6-BA 2. 00 mg·L~(-1)+NAA 0. 20 mg·L~(-1). The tubers with three leaves were cut and inoculated in the medium 1/2 MS+IBA 2. 00 mg·L~(-1),showing the highest rooting rate of 94. 00%. The rooting seedlings transplanted into the peat-vermiculite( 1 ∶ 1) matrix grew healthy and the survival rate was over 85. 00%. This research provided a novel solution for large-scale cultivation of P. cyrtonema seedling.

[Study on tissue culture and rapid propagation of Atractylodes macrocephala].

A study was conducted by tissue culture on the explant of Atractylodes macrocephala Koidz.. The result showed that NAA was a leading factor for induction of callus from leaf blades and the petiole as well as bud differentiation. MS + BA 1.0 mg/L + NAA 0.3 mg/L + GA3 0.2 mg/L was an optimal medium for induction of callus from leaf blades and the petiole and for the bud differentation also. MS + BA 3.0 mg/L + IBA 0.5 mg/L was suitable for the proliferation of axillary buds, with an induction rate of 95%. 1/2MS + IBA 0.1 - 0.5 mg/L was optimum for rooting, with a rooting percentage more than 90%. The survival rate of transplanted plantlets was more than 90%.